Over the years, pickup trucks have become very popular. Owners buy them not only for their utility, but for their looks. The utility aspect of a pickup truck would be increased if the bed of the truck could be tilted to convert the pickup truck into a small dump truck. There are many instances where a small dump truck or dump trailer is desirable. Municipalities have many instances where a small amount of sand, gravel, or asphalt needs to be delivered to a site. Landscapers, gardeners, and even home owners could make use of such a dumping vehicle. This type of vehicle reduces costs and increases efficiency by allowing multiple uses of trucks already being used for other purposes. For a product such as this to be commercially viable, this dumping function must be able to be added easily with tools generally available to the truck owner, without affecting the aesthetic appearance of the truck.
There are many different types of hoist mechanisms for pickup trucks that accomplish the dumping actuation of the conversion. Some are a small versions of scissor lift mechanisms used on large dump trucks, such as disclosed in U.S. Pat. No. 4,066,296. Other dump mechanisms are actuated through the use of a gas filled bag. Some use other means such as hydraulic cylinders. For a pickup truck hoist to be commercially successful, the conversion must not affect the appearance of the pickup truck and the conversion must be able to be accomplished with tools generally available to the truck owner. With varying degrees of success, manufacturers have been able to accomplish this for the hoist part of the conversion. Sometimes the manufacturers will provide a hinge kit for rotatably mounting the truck bed to the truck chassis. These typically are mounted directly between the truck chassis and the bed. This generally raises the truck bed by at least 3/4 of an inch (1.9 cm) or more. As disclosed in U.S. Pat. No. 4,168,861, the need to maintain the aesthetic appearance of the pickup truck by limiting the height that the truck bed is raised is essential. In pickup trucks of the prior art, a degradation of the body lines usually comes from having to raise the body substantially to install either the hoist or hinges. This degradation of the body lines, if substantially noticeable, would severely hamper the commercial viability of the product. Thus, an integral part of making a complete dump thick conversion to a pickup truck is the hinge and bumper attachment.
The method of hinging the bed and attaching the bumper on a pickup style of truck has always been a problem. Heretofore, pickup truck hoist manufacturers have left the bumper installation up to the truck owner or provided them with parts that must be taken to a weld shop to complete the bumper installation as disclosed in U.S. Pat. No. 4,168,861. Often, the truck owner is left to figure out how to attach the bumper. Frequently, the bumper is simply left off. Sometimes the truck owner is left to figure out how to cut off the bumper brackets so that they can be welded onto the bed hinge. That is also difficult because the typical truck owner does not have access to a welder. Hinge kits of the prior art have placed the pivot of the hinge toward the top of the chassis frame. That makes using the original bumper brackets an impossibility. The prior art has failed to provide a method of hinging the bed and attaching the bumper to the rotating part of the hinge with tools generally available to the truck owner.